Date: Fri, 9 Jun 2023 20:23:08 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Jeremy Schneider <schneider@ardentperf.com>,
	pgsql-hackers@lists.postgresql.org,
	Thomas Kellerer <shammat@gmx.net>,
	Tomas Vondra <tomas.vondra@enterprisedb.com>,
	Heikki Linnakangas <hlinnaka@iki.fi>, Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: Let's make PostgreSQL multi-threaded
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On Thu, Jun  8, 2023 at 11:37:00AM +1200, Thomas Munro wrote:
> It's old, but this describes the 4 main models and which well known
> RDBMSes use them in section 2.3:
> 
> https://dsf.berkeley.edu/papers/fntdb07-architecture.pdf
> 
> TL;DR DB2 is the winner, it can do process-per-connection,
> thread-per-connection, process-pool or thread-pool.
> 
> I understand this thread to be about thread-per-connection (= backend,
> session, socket) for now.

I am quite confused that few people seem to care about which model,
processes or threads, is better for Oracle, and how having both methods
available can be a reasonable solution to maintain.  Someone suggested
they abstracted the differences so the maintenance burden was minor, but
that seems very hard to me.

Did these vendors start with processes, add threads, and then find that
threads had downsides so they had to keep both?

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.